1. Field of the Invention
This invention relates to a method of emptying from a container a compressible load consisting of a plurality of items, apparatus for performing the method, a container to be emptied, and a container blank.
2. Description of the Prior Art
British Patent 1017036 discloses a method and apparatus for the removable of wrappers from bottles and the like. A parallelepipedic container contains rows of bottles with flanged necks. The material of the container may be paper, corrugated pasteboard, cardboard, light-metal foil, plastics, cloth, or other suitable material. The container with the bottles therein is advanced along a horizontal path at respective opposite sides of which are arranged two horizontal knives which cut through the container wall to form two cuts at those opposite sides, at a level a short distance below a top wall of the container. The container is then advanced along a second horizontal path at right angles to its first horizontal path and a horizontal knife at one side of the second path and at that same level cuts through the adjacent side wall of the container, so that the upper portion of the container is now free from the remainder of the container on three sides, and a vertical knife extending centrally of the path cuts through the leading side wall and the lagging side wall of the container, whilst a plurality of pointed bars extending longitudinally of the second path receive the flanged necks of the bottles among them and the container is pushed downward from the bottles by a plate inserted vertically downward between two rows of the bottles.
The method and apparatus of that British patent are designed specifically for use with bottles having flanged necks and are not generally suitable for a compressible load. For example, the knives used would very likely damage any compressible load in contact with walls being cut by the knives.
European Patent Application Publication 0059982 discloses a method and apparatus for removing a paperboard container from a pile of continuous stationery contained therein. The container comprises a cover, a bottom wall and at least three side walls which can be folded flat after removal of the cover. With the container at a processing station, a pair of jaws grasps the cover and carries it away, thus allowing the side walls to lie flat. A jack displaces an arm to push the pile of continuous stationery off the bottom wall onto a conveyor which carries the pile away. Suction cups on the ends of the jaws and connected to vacuum lines then grasp and carry away the unit consisting of the bottom and side walls. This method and apparatus are suitable for a cohesive load but not for a load consisting of a plurality of items, since these would very likely become disorientated or scattered.
Federal German Patent Application Publication 2546594 discloses a method and apparatus for packing folded cartons into a transport container. The folded cartons are accumulated into a horizontal row between end plates. Then a horizontal, handled yoke having further end plates resiliently urged inwards, but pressed outwards by the operative applying his thumb to a spring-load push-button, is manually applied over the top of the row. The operative releases the push-button to clamp the row between the end plates of the yoke, then carries the yoke, with the folded cartons gripped between its end plates, to the container, and presses the push-button to move the end plates resiliently outwardly to drop the folded cartons in the container.
In an existing method and apparatus for emptying a compressible load consisting of individual carton blanks out of a fibreboard case, the top wall of which is partially perforated along its edges, the top wall of the case is cut along its edges and, thereafter, the case together with its load, is turned upside down onto a horizontal supporting surface. FIG. 1 of the accompanying drawings is a top perspective view which illustrates the next step in the method. Suction cups 3 are lowered to and seize the inverted bottom wall 1c of the previously lower portion of the case 1. The suction cups are then raised to raise that lower portion, with the intention that the cartons blanks 2 should remain resting upon the horizontal support surface 13 in two rows 2a and 2b. Before the lower portion is completely removed from its load 2, grippers 4 are pressed against the ends of the rows 2a and 2b. One pair of grippers 4 is shown. Another pair will be disposed at the opposite ends of the rows, so that the rows are compressed between their respective pairs of grippers. Once the lower portion has been lifted off completely, the load of blanks 2 is transferred to its point of use.
A difficulty with this existing method and apparatus is that often the carton blanks catch on the edges or sides of the lower portion of the case and hence do not fall from the case ready to be gripped by the grippers 4.